Generally, mobile terminals supporting multi-modes may operate on networks with different modes, such as 4G, 3G, 2G or the like. For example, due to reasons such as congestion or weak signals, a mobile phone may fall from a top-priority network, such as a Long Term Evolution (LTE) network, to a low-priority network, such as a 3G or 2G network. In the related art, for example, in a 3GPP (3rd Generation Partnership Project) standard, it is stipulated that if a network having higher priority than a current network is detected, the mobile terminal needs to return to the network with higher priority. However, in some cases, the network itself may not provide an instruction, such as an identifier indicating its priority level. At this time, when the mobile terminal resides on a network with substantially lower priority while a higher priority network of a good condition is available, a re-selection condition may not be satisfied. That is, even if there is a network with substantially higher priority available, the mobile terminal may not quickly return to the network with substantially higher priority.